Vascular access devices (VAD) used to access a patient's vascular space without puncture using a hypodermic needle. Vascular Access Devices (VADs) include intravenous catheters, syringes, extension sets, stop cocks, tubing, high pressure extension tubing, and needleless access devices. These devices are used in patients where frequent access is required to the vascular space for delivery of treatment and withdraw of fluids. Indwelling vascular access devices are susceptible to infection and occlusion, requiring continued preventive maintenance. To ensure VADs are used properly and do not become occluded, standards of practice have been developed to maintain the indwelling VAD. These standards include a cleaning procedure, which is commonly referred to as a flush procedure. One form of VAD maintenance is a continuous saline dip where which a saline bag is connected to the VAD and provides continuous flow of saline solution to the patient through the VAD. This approach may put the patient at risk by delivering excess fluid to the vascular space.
An alternative method for vascular device maintenance, known as flushing, involves intermittent delivery of saline thru the VAD using a hypodermic syringe. One way to deliver intermittent saline to the VAD is to fill a hypodermic syringe fitted with a needle from a saline vial or ampoule. The filled syringe is then connected to the VAD and the saline is then flushed thru the VAD into the patient. Use of pre-filled saline flush syringes to deliver saline flush to VAD's offers improved safety and efficiency over manually filled hypodermic syringes.
It is important in the flush procedure not to draw blood back into the catheter where it can clot and seal the catheter, commonly referred to as “reflux”. In order to prevent blood reflux into the catheter the user is encouraged to maintain a positive pressure in the line during the flush procedure. This may involve clamping the IV line and withdrawing the syringe and cannula from the LV. port while still applying pressure to the syringe plunger rod during the flush procedure. When using a conventional syringe with an elastomeric stopper, the stopper is often compressed when it contacts the distal end of the syringe barrel at the completion of the flush procedure. When a user relieves the pressure to the plunger after the flush procedure is completed, the stopper will expand back to its normal size thereby withdrawing liquid from the catheter into the syringe barrel. This is undesirable, since it can cause blood to enter the catheter at the catheter distal end (reflux) where it will remain stationary until the next time the VAD is used.
Although a wide variety of catheters and I.V. ports can be adequately flushed using currently available syringe assemblies, as flushing practices change from continuous IV drip to intermittent flushing, there is a need for a new sterile, single use, pre-filled delivery device for maintenance of VAD's.